No idea if this would he possible but my starting idea here is using a server of some sort to grab the firebase notifications and push them all over one webocket similar to GMS. What I don’t know is how registering apps works. I know from micro g they register themselves to receive notifications but I’m not sure of what data is actually given to micro g or the relationship between the app and micro g/the web socket.
I wonder if we could use lspatch (or similar) to hook in and change that. I might have a project ahead of me. We’ll see.